As a migratory ungulate species, the chiru ( Pantholops hodgsonii ) primarily inhabits the Qinghai–Xizang Plateau. The population of the chiru has experienced a steady increase in recent years due to the implementation of rigorous conservation measures, including the establishment of nature reserves and legislation prohibiting hunting and killing. However, the study of chiru population ecology remains poorly understood duo to the unique and harsh natural conditions, as well as the seasonal migration and breeding patterns. In our study, we observed a higher overall population of the chiru (with average daily observations of 352 in 2012–2013 and 453 in 2023) and a demographic shift toward younger age groups (with juvenile percentage at 17.23% in 2023 and 15.85% in 2012–2013), implying the effectiveness of conservation efforts. But the marked increase in mortality rates among chiru warrants serious attention, particularly with regard to juvenile fatalities (from 1 death in 2012–2013 to 51 deaths in 2023). During past conservation efforts, the chiru population has gradually recovered; however, it is imperative to acknowledge the potential future risks due to accelerated climate change and intensification of human activity.